Kiefer is arguably one of the most important German painters since World War II. His works are layered with cultural references to myth, political history, literature, architecture, and music. Although best known as a painter (see Bohemia Lies by the Sea, 1997.4a,b), he has produced a prodigious number of works on paper (watercolors, mixed media, and prints) throughout his career that range in size from intimate to monumental.

In 1984–85, Kiefer made a series of works on paper incorporating manipulated black-and-white photographs of desolate landscapes with utility poles and power lines. Such works, like Heavy Cloud, were an indirect response to the controversy in West Germany in the early 1980s about NATO's stationing of tactical nuclear missiles on German soil and the placement of nuclear fuel processing facilities.

The title of this work and the lead cloud adhered to its top are blunt reminders of Kiefer's oxymoronic use of this heavy material to depict something usually thought of as vaporous and virtually weightless. The title puns on "heavy water," which Kiefer regards as "a synonym for radiation." In scientific parlance, heavy water is water in which heavy hydrogen has replaced ordinary hydrogen, enabling neutrons to split uranium in a process of nuclear fission. In nuclear reactors, the splitting of uranium heats fuel, which in turn can be used to produce electricity economically. Kiefer has pointed out that even though lead is used "to seal radiation, as an envelope for this very dangerous stuff," his Heavy Cloud has "a radiation leak," which is represented by the yellow shellac streaks seeping from the bottom of the lead cloud in the direction of the bleak landscape.